https://blog.wongcw.com/2022/05/08/%e7%ac%ac%e4%b8%89%e5%a4%a7cpu%e6%9e%b6%e6%a7%8brisc-v%e6%9c%89%e4%ba%86%e8%87%aa%e5%b7%b1%e7%9a%84%e5%b0%8f%e7%9b%ae%e6%a8%99%ef%bc%9a%e5%8f%96%e4%bb%a3x86-arm/